Thanks for the answer! =) It still happens when I do this. I think it must be another problem. I made two pictures of it.
In the first picture I painted in the green circle in one stroke which looks fine. In the red circle I took the pencil away and started a new stroke. I want this one to look like the green one, but it won't work...
In the second picture I painted with a small amount of the flow as you suggested.
